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Important Lcd Parameters; Display Errors - Acer FP558 User Manual

Lcd color monitor 15.1" (38.3cm) lcd panel size


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Field of applications:
Image processing
medical field
Standard workstation
Banks (confidential area)

Important LCD parameters

A. Viewing angle
The viewing angle is the display's visible field. If one were to imagine a vertical line in the centre of
the image and to pivot up and down and to the right and to the left from that point, then that is the
viewing angle.†Working ergonomically requires a viewing angle of at least 60
zontally and 45
vertically (up/down). If only two values are specified for horizontal and verti-
cal, the values for right and left, and for horizontal and vertical are added together. If this were the
case then this would provide a viewing angle of 120
B. Contrast
Contrast is the ratio between the light intensity of the brightest and the darkest point of an image.
High contrast values improve readability and ergonomics.
A display should in all instances attain contrast values of 100:1. This is a point on which LCD mon-
itors are clearly superior to monitors.
C. Response time
The response time is the time, which a TFT cell requires to switch on and switch off. †For standard
applications a response time of a maximum of 70 ms (milliseconds) is sufficient. If a more rapid
image build-up is required (e.g. the multimedia field), then values of a maximum of 30 ms are
D. Brightness
Brightness is the emitted luminous power over a specified area. Brightness is another point, on
which LCD monitors are superior to CRT devices. Traditional monitors create approx. 80 to 100 cd/
m² (candela per meter square). In the case of LC displays, values below 150 cm/m² are not accept-

Display errors

A. Pixel errors
Pixel errors are (unfortunately) unavoidable with today's production methods, if you want to manu-
facture displays at an economically sensible price.
A display with a resolution of 1024x768 dots therefore has 786432 pixels. Each pixel consists of the
three sub-pixels for red, green and blue. That makes 2,359,296 individual control transistors. It can
occur during production that one or several transistors is defective, which means that pixel errors
occur, in which a sub-pixel does not light up at all or does so all of the time.
Acer LCD Color Monitor User's Guide
Field of applications:
is several people are working at one
Standard workstation
Presentation tasks
Banks (public area)
horizontally and 90
(right/left) hori-
English 44


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